Pectoral girdle and shoulder 1 Flashcards
what are the 3 bony projections on the scapula
coracoid process
acromion
spine of scapula
what are the 4 muscles of the rotator cuff
subscapularis
infraspinatus
supraspinatus
teres minor
where does subscapularis originate
subscapular fossa on anterior surface of scapula
where does infraspinatus originate
infraspinous fossa on posterior surface of scapula
where does supraspinatus originate
supraspinous fossa on posterior surface of scapula
which surface of the scapula does teres minor originate from
posterior
what muscle inserts onto the anterior surface of the medial border of the scapula
serratus anterior
what muscle inserts onto the posterior surface of the medial border of the scapula
rhomboid muscles and levator scapulae
what are the rules for the upper limb for the movement of a joint in terms of muscles and tendons passing over the joint
if a muscle or its tendon…
- crosses anterior surface of joint: flex
- crosses posterior surface of joint: extend
- medial surface of joint: adduct
- lateral surface of joint: abduct
(note: not all movements will be possible at all joints)
what creates the bicipital groove
tendon of long head of biceps brachii
where do the rotator cuff muscles insert on the humerus
all insert onto greater tubercle except subscapularis which inserts into lesser tubercle
where does subscapularis insert
lesser tubercle of humerus
where does supraspinatus insert
greater tubercle of humerus
where does infraspinatus insert
greater tubercle of humerus
where does teres minor insert
greater tubercle of humerus
what muscles attach to the inferior surface of the clavicle
subclavius
pec major
deltoid
what muscles attach to the superior surface of the clavicle
trapezius
deltoid
sternocleidomastoid
pec major
describe the structure of the glenohumeral joint
synovial ball and socket joint (therefore surrounded by a capsule)
capsule is reinforced by ligaments to help prevent dislocation of joint
the glenohumeral ligaments pass where
from lesser tubercle of the humerus to the edges of the glenoid cavity
the coracohumeral ligament passes where
from the greater tubercle of the humerus to the coracoid process of the scapula
the synovial lining of the glenohumeral joint extends away from the joint as what
bursae
what is a bursae
synovial pocket that may or may not be in communication with the joint
where is there a bursae in the shoulder
around the proximal part of the tendon of the long head of the biceps as it passes through the bicipital groove
how is the tendon of the long head of the biceps held within the bicipital groove
small transverse humeral ligament
what is the only bony link between the body and the upper limb
the clavicle which passes between the sternum and the scapula
name the ligaments of the clavicle
- acromioclavicular ligament
- coracoacromial ligament
- coracoclavicular ligament
- A and P sternoclavicular ligaments
- costoclavicular ligament to 1st rib
- interclavicular ligament between clavicles
what are the parts of the coracoclavicular ligament
conoid and trapezoid parts
what do the anterior and posterior sternoclavicular ligaments joint between
manubrium and clavicle
the joint between the manubrium and clavicle is what kind of joint
synovial saddle joint
how are the scapula and the muscles that surround it supplied with blood
anastomosis around the scapula
blood supply for the scapula and the muscles that surround it is from where
branches of the subclavian artery
the right subclavian artery is a branch of what
brachiocephalic trunk
the left subclavian artery is a branch of what
arch of the aorta
the vertebral arteries (branches of the subclavian) unite to form what
basilar artery that supplies the brain
what does the subclavian artery become and at what point
becomes the axillary artery as it emerges from beneath the clavicle and passes over surface of the first rib
branches from what supply the scapula and the proximal humerus
thyrocervical trunk and the axillary artery
the dorsal scapular artery comes from where
the dorsal scapular artery is the deep branch of the transverse cervical artery from the thyrocervical trunk from the subclavian artery
where does the dorsal scapular artery pass
passes down the medial border of the scapula and anastomoses with branches from the suprascapular artery (from the thyrocervical trunk) and the subscapular artery (from the axillary artery)
the dorsal scapular artery anastomoses with what
branches of the suprascapular artery and branches of the subscapular artery
the suprascapular artery comes from where
thyrocervical trunk
the subscapular artery comes from where
the axillary artery
what supplies the muscles at the lateral border of the scapula
subscapular artery forms the thoracodorsal artery that supplies muscles of the lateral border of the scapula
how many anatomical spaces are assoc. with the muscles attaches to the posterior surface of the scapula and the proximal humerus
2
what are the two spaces that are assoc. with the muscles attaches to the posterior surface of the scapula and the proximal humerus called
quadrangular space
triangular space/hiatus/interval
quadrangular space: superior border
teres minor
quadrangular space: inferior border
teres major
quadrangular space: medial border
long head of the triceps brachii
quadrangular space: lateral border
humerus
what 2 structures pass through the quadrangular space
axillary nerve
posterior circumflex humeral artery
what nerve supplies the deltoid and teres minor
axillary nerve (C5 C6)
triangular space: superior border
teres major
triangular space: medial border
long head of triceps brachii
triangular space: lateral border
humerus
what 2 structures pass through the triangular space
radial nerve and profunda brachii artery
what nerve supplies triceps brachii
radial nerve
what nerve supplies the posterior compartment of the arm
radial nerve
what is the innervation of pectoralis major
medial (C8-T1) and lateral (C5-7) pectoral nerves
where do the medial (C8-T1) and lateral (C5-7) pectoral nerves come from
from the medial and lateral cords of the brachial plexus
what are the attachments of pec major
clavicle, costal cartilages ribs 1-6, sternum to the outer lip of bicipital groove of the humerus
what actions does pec major do
flexes arm at the shoulder
adduction of the arm
medial rotation of arm at shoulder
what is the innervation of pec minor
medial pectoral nerve (C8,T1) from medial cord of brachial plexus
what are the attachments of pec minor
3rd 4th and 5th ribs to coracoid process of scapula
does pec minor cross the glenohumeral joint
no
what actions does pec minor do
- pulls shoulder anterior and inferior (pulls scapula forwards)
- can elevate ribs if shoulder is fixed
- stabilises the shoulder during movements of the upper limb
what is the innervation of serratus anterior
long thoracic nerve (C5,6,7) of the brachial plexus
what are the attachments of serratus anterior
outer surface upper 8 ribs to medial border of the scapula
what is the action of serratus anterior
protraction of the scapula
what is the innervation of trapezius
spinal accessory nerve (CN XI, motor)
cervical plexus C3,4 (pain)
what is the motor innervation of trapezius
spinal accessory nerve (CN XI)
what is the pain innervation of trapezius
cervical plexus C3,4
how can trapezius preform more than one action
fibres that pass in several different directions
what are the attachments of trapezius
superior nuchal line, nuchal ligament, spinous processes of C7-T12 to lateral 1/3 of clavicle, acromion and spine of scapula
what are the 3 parts of the trapezius
ascending part, transverse part, descending part
what does the ascending part of the trapezius do
depress scapula
what does the transverse part of the trapezius do
retracts scapula
what does the descending part of the trapezius do
elevate scapula
rotate glenoid cavity
how does trapezius allow the arm to move above the head
rotates scapula - tilts the glenoid cavity moving the acromion superiorly and allowing the humerus to elevate
what actions can trapezius do
elevate, depress and retract the scapula
also rotate the scapula
what is the innervation of latissimus dorsi
thoracodorsal nerve from posterior cord brachial plexus (C6-8)
what are the actions of latissimus dorsi
extension, medial rotation and adduction of the arm
what are the attachments of latissimus dorsi
ilium, thoracolumbar fascia, spinous process of lower 6 thoracic vertebrae to floor of bicipital groove of humerus
latissimus dorsi is useful in what
climbing, chin ups
what is the innervation of levator scapulae
direct C3 4 5 via dorsal scapular nerve
what are the actions of levator scapulae
help control scapular position
elevate shoulder (with trapezius)
shoulder fixed can laterally flex neck to same side
what are the attachments of levator scapulae
transverse processes of atlas, axis, 3rd and 4th cervical vertebrae to medial scapular border between superior angle and medial end of scapular spine
what is the innervation of rhomboid major and minor
dorsal scapular nerve C4-5
the rhomboids lie inferior to what muscle on the posterior body wall
trapezius
what are the attachments of rhomboid major
from 2-5 thoracic spines to medial border of scapula (spine to inferior angle)
what are the attachments of rhomboid minor
nuchal ligament and C7 to T1 thoracic spines to medial end of spine of scapula
what do the rhomboids do
retract scapula
what muscle forms a cap over the shoulder
deltoid
what is the innervation of deltoid
axillary nerve (C5,6) from posterior cord of brachial plexus
what are the attachments of deltoid
lateral 1/3 clavicle, acromion, spine of scapula to deltoid tuberosity of humerus
the bulk of the muscle fibres of deltoid lie _____ to the glenohumeral joint
lateral
what are the actions of deltoid
abduction of arm from 10-110 degrees
extension and lateral rotation of arm
flexion and medial rotation of arm
the initial 10 degrees of abduction is performed by what
supraspinatus
abduction of the arm from 10-110 degrees is done mostly by what fibres of deltoid
middle
extension and lateral rotation of arm is done by what fibres of deltoid
posterior fibres
flexion and medial rotation of arm is done by what fibres of deltoid
anterior fibres
the fibres of deltoid that attach to the clavicle do what
flex arm
the fibres of deltoid that attach to the spine of the scapula do what
extend arm
what is the insertion of deltoid
all the fibres come together at a common insertion point - the deltoid tuberosity of the humerus
what is the delto-pectoral groove
groove between deltoid and pec major on anterior body wall
what lies in the delto-pectoral groove
cephalic vein
what does the cephalic vein drain
blood from skin and superficial fascia from lateral side of dorsum of hand, forearm and medial side of arm
the cephalic vein pierces the ______ ___ to enter the ___ and join the ____ ___
clavipectoral fascia
axilla
axillary vein
what is the innervation of teres major
subscapular branch of posterior cord of brachial plexus (lower C5-6)
what are the attachments of teres major
lateral border of scapula (lower 1/3, posterior) to medial lip of bicipital groove of humerus
what are the actions of teres major
adduction and medial rotation of arm
what is the innervation of subclavius
nerve to subclavius C5,6
what are the attachments of subclavius
sternal end of 1st rib to middle 1/3 of underside of clavicle
what are the actions of subclavius
draws clavicle down and slightly forwards during abduction
